/**
 * Created by minigci.he on 16/9/21.
 */

let arr = ['a', 'b', 'c']
let iter = arr[Symbol.iterator]();

console.log(iter.next())    // {value: "a", done: false}
console.log(iter.next())    // {value: "b", done: false}
console.log(iter.next())    // {value: "c", done: false}
console.log(iter.next())    // {value: undefined, done: true}
